the products had ceased the temperature of the reaction mixture was raised to 250ºC when 1,2,4-triazole 3
1
9
(
0.34 g, 33%) distilled off (mp 121ºC, heptane). The mixture of products 11 and 12 (1:0.8 according to
NMR) contained in the first fraction was separated by fractional distillation.
-Trifluoromethyl-1,2,4-triazole (11). Colorless very volatile liquid. Yield 0.28 g (14%). Bp 67-70ºC.
F
1
1
19
H NMR spectrum, δ, ppm: 8.09 (1H, s, CH); 8.49 (1H, s, CH). F NMR spectrum, δ, ppm: -60.37 (s, CF
3
).
+
Found: m/z 137.1 [M] . C H F N . Calculated: M 137.1. Found, %: N 30.28. C H F N . Calculated, %: N 30.65.
3
2
3
3
3
2
3
3
1
-Difluoromethyl-1,2,4-triazole (12). Colorless very volatile liquid. Yield 0.11 g (6%). Bp 98-101ºC.
1
1
2
H NMR spectrum, δ, ppm (J, Hz): 7.22 (1H, t, JH,F = 60.3, CHF
F NMR spectrum, δ, ppm: -95.41 (d, JF,H = 60.3, CF
2
); 8.00 (1H, s, CH); 8.48 (1H, s, CH).
9
2
+
2
H). Found: m/z 119.1 [M] . C
3
H
3
F
2
N
3
. Calculated:
1
19.1. Found, %: N 35.00. C H F N . Calculated, %: N 35.30.
3 3 2 3
1
-Trifluoromethyl-3-methylimidazolium Iodide (13). A solution of imidazole 8 (0.045 g, 0.36 mmol)
and MeI (0.1 g, 0.7 mmol) in acetonitrile (5 ml) was heated for 16 h at 70ºC. Solvent was distilled off in vacuo
and the residue was crystallized from ethyl acetate. Yield 75 mg (75%). Colorless crystalline material. Mp
1
2
06-208ºC. H NMR spectrum, δ, ppm: 4.10 (3H, s, CH ); 7.77 (1H, s, CH); 8.22 (1H, s, CH); 10.00 (1H, s,
3
1
9
CH). F NMR spectrum, δ, ppm: -57.20 (s, CF ). Found, %: I 45.65; N 10.10. C H F IN . Calculated, %:
3
5
6
3
2
I 45.64; N 10.08.
3
-Butyl-1-trifluoromethylimidazolium Iodide (14). A solution of imidazole 8 (0.85 g, 6.25 mmol) and
1
9
BuI (2.3 g, 12.5 mmol) in acetonitrile (25 ml) was heated for 96 h at 70ºC, monitoring the reaction from the F
NMR spectra. Solvent was distilled in vacuo and the residue was crystallized from ethyl acetate. Yield 1.8 g
1
(
90%). Colorless crystalline material. Mp 148-150ºC. H NMR spectrum, δ, ppm: 0.95-1.00 (3H, m,
CH CH CH CH ); 1.40-1.52 (2H, m, CH CH CH CH ); 2.02-2.11 (2H, m, CH CH CH CH ); 4.61-4.70 (2H, m,
2
2
2
3
2
2
2
3
2
2
2
3
1
9
CH CH CH CH ), 8.40 (1H, s, CH); 8.47 (1H, s, CH); 10.78 (1H, s, CH). F NMR spectrum, δ, ppm: -57.90 (s,
2
2
2
3
CF ). Found, %: I 39.47; N 8.73. C H F JN . Calculated, %: I 39.65; N 8.75.
3
8
12
3
2
3
-Butyl-1-trifluoromethylimidazolium Ditriflylamide (15). Lithium ditriflylamide (0.7 g, 2.5 mmol)
was added to a solution of iodide 14 (0.65 g, 2 mmol) in water (15 ml) and stirred for 3 h at 40ºC. The product
was extracted with dichloromethane (3×20 ml) and the extract was washed with water (2×10 ml) and dried over
MgSO . Solvent was distilled off and the residual solvent was evaporated in vacuo (0.05 mm Hg, 80ºC, 10 h).
4
1
Yield 0.86 g (91%). Colorless liquid. Vitrification temperature -77ºC*. H NMR spectrum, δ, ppm: 0.95-1.01
(
(
-
3H, m, CH CH CH CH ); 1.35-1.44 (2H, m, CH CH CH CH ); 1.82-2.00 (2H, m, CH CH CH CH ); 4.20-4.33
2 2 2 3 2 2 2 3 2 2 2 3
1
9
2H, m, CH CH CH CH ); 7.60 (1H, s, CH); 7.67 (1H, s, CH); 9.78 (1H, s, CH). F NMR spectrum, δ, ppm:
2
2
2
3
58.89 (3F, s, NCF ); -80.30 (6F, s, 2SO CF ). Found, %: C 25.24; H 2.82; N 8.48; I < 0.5. C H F N O S .
3
2
3
10 12
9
3
4 2
Calculated, %: C 25.38; H 2.56; N 8.88.
-Butyl-1-trifluoromethylimidazolium Tetrafluoroborate (16). A solution of salt 14 (1.46 g,
.56 mmol) in dichloromethane (10 ml) was added to a solution of AgBF (0.89 g, 4.56 mmol) in
3
4
4
dichloromethane (20 ml). The reaction mixture was stirred for 15 min at 25ºC. The residue was separated by
centrifugation and washed with dichloromethane (10 ml). Solvent was distilled off in vacuo (15 mm Hg) and the
residual solvent was removed in vacuo (0.05 mm Hg, 80ºC, 8 h). Yield 1.26 g (99%). Colorless crystalline
1
2
material. Mp 82-83ºC. H NMR spectrum, δ, ppm (J, Hz): 0.14 (3H, t, J = 7.5, CH CH CH CH ); 0.63 (2H,
H,H
2
2
2
3
2
2
2
sext, J
= 7.5, CH CH CH CH ); 1.23 (2H, q, J
= 7.5, CH CH CH CH ); 3.71 (2H, J
H,H
= 7.5,
H,H
2
2
2
3
H,H
2
2
2
3
1
9
CH CH CH CH ); 7.34 (1H, s, CH); 7.59 (1H, s, CH); 9.10 (1H, s, CH). F NMR spectrum, δ, ppm: -58.68 (3F,
2
2
2
3
s, CF ); -151.17 (4F, s, BF ). Found. %: C 34.00; H 4.52; N 9.96; I < 0.5. C H BF N . Calculated, %: C 34.32;
3
4
8
12
7
2
H 4.32; N 10.00.
_
*
2
______
The vitrification temperature was determined using a DSK-D differential scanning calorimeter. Heating rate
ºC/min. We express our sincere thanks to G. V. Titov (Institute of Macromolecular Chemistry of the National
Academy of Sciences of Ukraine) for determining the vitrification temperature
4
34